Apparatus for producing high octane rating motor fuel



Jan. 14, 1941. MASCHWITZ 2,228,882

APPARATUS-FOR PRODUCING HIGH OCTANE RATING MOTORFUEL Original Filed June 28, 1935 2 Sheets-Sheet,l

7205 FFac/1?na/0r\ fl97\ Sa em/afar INVENTOR ATTORN EY Jan. 14, 1 941. P. A. MAscHwrrz 2,228,882

APPARATUS FOR PRODUCING HIGH-OCTANE RATING MOTOR FUEL Original Filed June 28, 1935 2 Shets-Sheet 2 Fracf/bmfon erai ass urz'j JMJ/ -DQ,

ATT OR N EY Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE APPARATUS FOR PRODUCING HIGH OCTANE RATING MOTOR FUEL Percy A. Masch-witz, Toledo, Ohio, assignor to The Pure Oil Company, Chicago, Ill., a corporation of Ohio Claims.

This appiication is a division of application Ser. No. 28,866, filed June 28, 1935, entitled Method for producing high octane rating motor fuel. This invention relates to apparatus for producing high octane hating gasoline and is more particularly concerned with apparatus for convertin'g hydrocarbon oils under high pressure into motor fuels and simultaneously polymerizing hydrocarbon gases, produced in the conversion, to, motor fuel.

One of the objects of my invention is to provide apparatus for simultaneously distilling crude oil, cracking heavy oil, reforming naphtha, and polymerizing hydrocarbon gases in a single furnace structure.

Another object of my invention is the provision of apparatus for cracking oils and reforming naphtha under high pressures and for polymerizing the gases resulting from the cracking and reforming operations under high pressures without the necessity of compressing the gases.

A further object of my invention is the provision of apparatus whereby distillation and cracking of oil and polymerization of gases may be carried out as a unitary process or the distillation and/or cracking maybe carried out independently of the polymerization step.

Still another object of my invention is to provide apparatus for increasing the yield of gasoline obtainable from crude oil or other "charging stock.

A still further object of my invention is to produce a larger amount of gasoline of high octane rating than has heretofore been produced from crude oil.

Other objects of my invention Will be apparent from the following detailed description considered in connection with the accompanying drawings of which,

The single figure is a diagrammatical, vertical view illustrating one form of the invention.

Referring to the drawings, the numeral l indicates a storage tank from which'crude oil may be withdrawn by means of pump 3 through line 5 and charged to a heating coil 1 located in the convection zone 9 of a suitable furnace indicated generally by the numeral H. The convection zone of the furnace may be heated by a suitable burner l3 located in the combustion section I5. During its passage through the heating coil 1 the oil may be heated to a temperature of approximately 700 to 800 F. After passing through the heating coil the oil is discharged therefrom through the line H into an intermediate point of the vaporizer and fractionato-r IS. The volatile portions including the gas oil pass overhead through the line 2| and the heavy residuum is withdrawn from the bottom of the vaporizer through the line 23 and valve 25. The vapors are discharged from the line 2l into an intermediate point of the frao'tionating tower 21 from which a light naphtha fraction may be taken overhead through the line 29. A heavy naphtha fraction may be taken off .as a side stream through the line 3| and the gas oil may be discharged from the bottom of the tower through the line 3.3. The light naphtha taken overhead as vapor may be passed through the cooling coil 35 where it is condensed and then collected in separator 31. Any gas formed during the distillation may be withdrawn from the top of the separator 31 through line 39 and valve 4|. The heavy naphtha withdrawn as a side stream through the line 3| may be passed through the cooling coil 43 and collected in a tank 45. From the separator 31 the light naphtha. is withdrawn through the line 41 and valve 49 and sent to a collecting tank 5| through the line 52. A portion of the light naphtha from the separator 31 may be returned as reflux to the top of the tower 21 through line 53 by means of pump 54. A line 55 having a valve 56 is provided for withdrawing heavy naphtha from the system.

The gas oil, withdrawn through the line 33, may be pumped by means of pump 51 and charged through line 59 and valve M to the line 63 where it acts as a cooling medium to shock chill the reaction products discharged from the cracking coil 65. If necessary, suitable heat interchangers may be placed in the line 59 to cool the gas oil. A line 51 having valve 69 therein is provided for withdrawing gas oil from the line 33 when it is desired to shut down the cracking still 65 for cleaning or repairing.

The cracking coil 65 is located in a separate section 1| of the furnace l1 and is heated chiefly by means of radiant heat supplied by the burner 13. The oil undergoing cracking is preferably charged to the coil 65 at a pressure of from 500 to 1500 pounds per square inch and heated therein to a temperature of from 800 to 1000 F. The reaction products which have been cracked in the heating and conversion coil 65 are discharged through the line 63 and are shock chilled to a temperature below conversion temperature by the gas oil supplied through the line 59. If desired, a suitable reaction chamber may be connected to the outlet of the coil 65 to provide additional time for the cracking reaction to take place. The chilled products may then pass through a suitable heat exchanger and cooling coil 11 where they are cooled sufiici-ently to lower their temperature to approximately 450 to 600 F. and then passed into the upper section of the fracti-onating tower I0. The fractionating tower I9 is preferably maintained under the high pressure of the cracking system and is operated under such conditions that substantially nothing heavier than butane passes over as vapors. For this purpose the top temperature of the tower may be maintained at from 200 to 300 F. The gases are taken oif the top of the tower through the line BI and partially condensed by passing through cooling coil 83. The resulting liquid and gases are passed to the separator from which uncondensed gases consisting chiefly of methane, ethane, and hydrogen and some ethylene are bled off through the line 81 and valve 80.

The liquids collected in the bottom of the fractionating tower 19 may be passed by means of line through heat interchanger I5 and then through a heating coil 9| located in the convection section 9 where the oil is heated to a temperature of approximately 700 to 800 F. and discharged into the line 93, then through pressure release valve into a vaporizer 9?. The heavy tar may be Withdrawn from the vaporizer 91 through line 90 and valve IOI and the vapors including the gas oil are taken ofi overhead through the line I03 and discharged into an intermediate point of the fractionating tower I05. The fractionating tower I05 is maintained under pressure approaching atmospheric and under such temperatures that only the fractions within the gasoline boiling range are taken overhead as vapors. The vapors are taken from the top of the fractionating tower I05 through the line I01 and are condensed by passing through condenser I00. The condensate passes into the separator III from which gases, if any, are bled from the system through the line II3 and valve H5. The condensate is in part withdrawn from the bottom of the separator III by means of the pump H9 and charged through line HI and valve I23 into the top of fractionating tower I05 to act as refiux liquid. The remainder of the condensate from separator III may be withdrawn from the bottom thereof through line I25 from which all or a portion thereof may be withdrawn by pump I21 through line I29 and valve I3I; or the remainder may in whole or in part be withdrawn from the system through line I33 controlled by valve I35, or may be sent through line I31 controlled by valve I39 into the collecting tank 5| through valve I40 and line 52.

The liquid fraction collecting in the bottom of fractionating tower I05 is Withdrawn therefrom by means of pump I5I through line I43 and charged to the inlet of cracking coil 65 under pressure between 500 and 1500 pounds per square inch.

An absorption liquid, which may be an intermediate cut withdrawn from the fractionating tower I05 through the line I53, valve I54, cooling coil I55, vessel I57, and pump I59, or the heavy naphtha collected in the vessel 45, may be charged by pumps I59 and I6I through the lines I03 and I65 and valve I65, respectively, into the top of the absorption tower I00 wherein it flows downward in counter-current relation with the rising stream of gases. The absorption tower is preferably operated under pressures of approximately to 210 pounds per square inch and approximately atmospheric temperature. Gases containing olefinic hydrocarbons are fed into the bottom of the absorber through line I 61. The fixed dry gases which may be chiefly methane, ethane, ethylene, and hydrogen, are bled from the top of the absorber through the line I08 and valve I59 to any suitable point, for use as fuel or for other purposes. The absorber oil charged with dissolved gases may be withdrawn from the bottom of the absorber I66 by means of the pump IlI through line I13 and valve I14 and charged into the separator 85 where it commingles with the liquefied gases coming from the fractionating tower I9. The combined products may be withdrawn from the lower portion of the separator 85 by means of pump I75 through the lines I16 and IT! and valve I19 and charged into the inlet end of the polymerizing and reforming coils I80. A portion of the products from the bottom of the separator 05 may be passed into the top of the tower I9 through valve controlled line IBI to act as reflux. The coils I80 are located in a separate section I82 of the furnace II, and are heated chiefly by radiant heat from the burner I83. The combined charge of heavy naphtha and liquefied gases is heated to a temperature of approximately 900 to 1100 F. under pressures of approximately 500 to 1500 pounds per square inch in the coils I80. Upon leaving the coils I80 through the line I85, the reaction products are shock chilled by injecting therein through the line I81 a portion of the pressure distillate withdrawn from the separator III, through line I29. If desired, a reaction chamber may be connected to the outlet of the coils ISO to provide additional reaction time for the products undergoing conversion. Distillate from an extraneous source may be fed through line I88 and valve I80 and used as chilling fluid in place of or together with condensate from separator III. The reaction products which have been chilled to a temperature below conversion temperature, preferably 550 to 700 B, may then be passed through either line I90 and valve I9I into a clay treating chamber I93, or may be by-pas'sed around the chamber I03 through line I85 and valve I91 into fractionating tower I99.

The chamber I93 may be filled with a suitable solid adsorptive catalyst such as fullers earth or similar clay, and is preferably maintained under the pressure existing in the coil I30. During the passage through the clay tower the conversion products are decolorized and degummed. After treatment with the adsorptive catalyst, all the products undergoing treatment may be withdrawn from the tower I93 through the line 20I and valve 202 and charged into an intermediate point of the fractionating tower I99. The fractionating tower I93 is preferably operated under super-atmospheric pressure of approximately 1'75 to 225 pounds per square inch. The liquid collecting in the bottom of the tower I99 may be withdrawn through line 203 and valve 204 and charged into vaporizer 01. The uncondensed vapors which may include the major portion of the gasoline fractions, and the uncondensable gases, may be withdrawn from the top of the fractionating tower I00 through the line 205 and condenser 20'! and pass into the gas separator 209. The condensate may be withdrawn from the separator 203 by means of the pump 2II through the line 2I3 and a portion thereof returned to the top of the fractionating tower I99 through the line 2l5 and valve 2|! to act as reflux. The remainder of the condensate may be discharged through line 2!!! and valve 220 into line 22I, heat interchanger 222, into an intermediate point of the stabilizer 225; The stabilizer is preferably operated under super-atmospheric pressure of 175 to 250 pounds per square inch and under temperature conditions suitable to 5 separate the light ends unsuitable for gasoline, as an overhead which is withdrawn from the tower through the line 221. For this purpose a temperature of approximately 120 to 150 F. is maintained at the top of the stabilizer. The overhead products are then cooled by passing through cooling coil 229 and discharged into separator 23L The gases from the top of the separator 23I are withdrawn through the line 233 and valve 234 and may be charged to the bottom of the absorption tower I60 where the heavy fractions such as propane, propylene, butane and butylene, are absorbed. Gases which come oil the top of the separator 209 are bled into the line 233 by means of the line 235 and also charged to the absorber. Any liquids collected in the separator 23I may be discharged therefrom by means of pump 231 through line 239 and valve 24I into the top of the stabilizer 225 to act as reflux. The stabilized gasoline may be withdrawn from the bottom of the stabilizer 225 through line 226, the heat interchanger 222 and cooling coil 243 through line M5 and valve 241 into the collecting tank 5 I.

A line 250 having a valve 252 therein is provided for passing liquefied gases from the separator 05 directly to the line 22! and stabilizer 225 when it is desired to operate the cracking portion of the system without operating the reforming and polymerizing portion. A line 254 having valve 256 is connected to the top of gas separator 'ZEI for the purpose of withdrawing gases from the system when the reforming and polymerization unit is not in operation.

The furnace II is preferably built in sections 40 with heating means for each section so that any one section may be shut down and the other sections be operated independently thereof. As shown in the drawings, the furnace-has bridge walls separating the furnace into three separate heating sections and the products of combustion are withdrawn from the bottom of the furnace.

Any suitably designed furnace may be used instead.

As a specific example of one method of carrying out my invention, crude oil may be rapidly heated in the coil I to a temperature of approximately 750 F. and discharged into the vaporizer and fractionator I9 from which heavy residuum may be withdrawn. The vapors coming off the top of the vaporizer or fractionato-r are further fractionated in tower 21 into a heavy portion constituting the gas oil fraction, an intermediate condensate constituting the heavy naphtha boiling between 200 and 600 F., and vapors constituting the light naphtha. The light naphtha may be withdrawn through the line 29 and after cooling and separation of gas, collected in the tank 5!. The top of the fractionating tower may be maintained at a temperature of from 250 to 300 F. 5 The heavy naphtha, after having been cooled to approximately atmospheric temperature, is charged to the top of the absorption tower I66 where it is contacted with the gases entering the bottom of the absorption tower through line I61. 70 The absorption tower may be maintained at a pressure of approximately 200 pounds per square inch and at a temperature approximately atmospheric. Under these conditions the major portion of the propane, propylene, butane and butyli5 ene is absorbedtogether with a portion of the ethylene, and the dry gases consisting chiefly of methane, ethane, ethylene, and hydrogen escape from the top of the tower through the line I68. These gases are used for fuel or any other suitable purpose.

The gas oil fraction collected in the fractionating tower I05 may be charged to cracking coil 65 at a pressure of approximately 1000 pounds per square inch and heated therein to a temperature of approximately 925 F. The products leaving the cracking coil may be immediately chilled to a temperature of 700 F. by injecting therein the gas oil from the bottom of the tower 21. The chilled products may then be cooled sufiiciently to lower their temperature to approximately 600 F, and charged at this temperature into the fractionating tower I9 which may be maintained under a pressure of approximately 600 pounds per square inch. The top of the tower may be maintained at a temperature of approximately 250 F. Under these conditions of temperature and pressure, nothing heavier than butane will escape as an overhead product. The vapors may then be cooled to approximately atmospheric temperature under existing pressure and the heavier portions of the gas such as the propane, propylene, butane, and butylene, will liquefy. The liquid products from the fractionator I9 may then be heated to a temperature of approximately 750 F. and charged into the vaporizer 91 where the pressure is reduced to approximately 15 pounds per square inch. Substantially everything except the tar will pass overhead as vapors and the vapors are fractionated in the tower I05 into gasoline distillate, heavy naphtha, and gas oil. The fractionating tower I05 may be maintained under a pressure of approximately atmospheric to 15 pounds per square inch, and the top of the tower may be maintained at a temperature of approximately 350 F. Additional oil for absorption'may be withdrawn as a side out from the fractionating tower I05 when necessary.

The liquefied gases plus the absorbent oil charged With dissolved gases may be charged from separator to the heating and reaction coils I80 at a pressure of approximately 1000 pounds per square inch and heated therein to a temperature of approximately 1000 F. In the coils I80 the heavy naphtha. is reformed into high octane rating naphtha and part of the dissolved gases are polymerized to heavier hydrocarbons boiling chiefly within the gasoline range. The products leaving coils I80 are immediately chilled to a temperature of approximately 550 F. and may be passed at this temperature through the clay tower I93 wherein the color-imparting and gum-forming constituents are polymerized to heavy hydrocarbons which may be subsequently removed by fractionation. The pressure in the clay tower is maintained at approximately the pressure of the heating and reaction. coils I80. Pressure on the products leaving the clay tower may be partially reduced and the products then charged into vaporizing and fractionating tower I at a pressure of approximately 200 pounds per square inch where separation into gasoline vapors and heavier liquids takes place. The temperature at the top of the tower may be maintained at approximately 450 F. The gasoline vapors leaving the top of the fractionating tower I90 are condensed and the condensate passed to the stabilizer tower 225 which may be maintained under a pressure of approximately 225 pounds per square inch. The temperature of the top of the stabilizer is maintained at approximately 120 F. and the bottom of the tower is maintained at approximately 300 F. Under these conditions the gasoline is freed of fractions lighter than butane. The gases from the stabilizer together with gases from the tower I99 are charged to the bottom of the absorber. The oil charged with dissolved gases may be commingled with liquefied gas in separator 85.

When it is desired to shut down the cracking and polymerizing units for cleaning, repairing or other reason, the running of the crude oil through the coils I may be continued without interruption by closing valve 6I in line 59 and valve I65 in line I64. The gas oil will then be withdrawn from the tower 2'! through line 33, line 61 and valve 69, The heavy naphtha will be withdrawn from the vessel 45 through line 55 and valve 56. Burners I3 and I83 in sections II and I82, respectively, of furnace II will be shut oif.

When it is desired to run the cracking unit and shut down only the reforming and polymerizing unit, the coil I85, the clay chamber I93, the fractionating tower I99 and the absorber I66 will remain idle. To isolate the coil I80, valve I19 in line I'II will be closed. To isolate the chamber I93, the valve I9I in line I96 as well as valve 202 in line 20I will be closed. To isolate the fractionating tower I99, valve 294 in line 263 and valve 220 in line 2I9 will be closed. To isolate the absorber I66, valve I54 in line I53, valve I65 in line I64, valve I'M in line I13, and valve 234 in line 233 will be closed. The burner I83 in section I82 of furnace II will be shut off. The heavy naphtha from tank 45 may be withdrawn from the system through line 55, the gasoline collected in separator I II may be sent to collecting tank 5| or withdrawn from the system through line 533 for chemical treatment, and the liquefied gases in separator 85 may be sent directly to the stabilizer through lines 256 and HI. The gases from separator 23I may be bled from the system through line .254 and valve 256.

It will be observed that by means of my invention I have completely eliminated the necessity for compressing gases and the expense attendant therewith. All the products are pumped through the process in the liquid phase thereby enabling the system to handle much larger throughputs than is possible where the products are processed in the vaporous or gaseous phase.

Although I have set forth certain conditions of temperature and pressure in various parts of the system, it is to be understood the invention is not limited to the conditions stated but that the invention is intended to broadly cover a system. of cracking, reforming, and polymerizing in which products are handled in the liquid state without the necessity of compressing the gases.

What I claim is:

1. Apparatus of the character described comprising a heating coil, means for charging hydrocarbon oil to said coil, a vaporizer connected to said coil, a fractionator connected to said vaporizer, a second heating coil and a second fractionating tower connected to the outlet of said second coil, a line connecting the lower portion of said first fractionator to the outlet of said second coil, means connecting the lower portion of said second fractionating tower to the inlet of said second coil, a condenser connected to the top of said second fractionator, a gas-liquid separator connected to said condenser, a third heating coil, a line connecting the lower portion of said gas-liquid separator to the inlet of said third coil, a gas-liquid separator connected to the outlet of said third coil, an absorber, a line connecting the upper portion of said last mentioned gas-liquid separator to the lower portion of said absorber, a line connecting the intermediate portion of said first mentioned fractionator to the upper end of said absorber, and a connection from the lower end of said absorber to the inlet of said third heating coil.

2. Apparatus in accordance with claim 1 including a vaporizer connected to the lower end of said second fractionating tower, a fractionating tower connected to the top of said vaporizer, and a line connecting the lower end of the last-mentioned fractionating tower to the inlet of said second heating coil.

3. Apparatus in accordance with claim 1 including a vaporizer connected to the lower end of said second fractionatin tower, a fractionating tower connected to the top of said vaporizer, a line connecting the lower end of the lastmentioned fractionating tower to the inlet of said second heating coil, and a line connecting the intermediate portion of the last-mentioned fractionating tower to the upper portion of said absorber.

4. Apparatus in accordance with claim 1 including means for withdrawing the liquid products from said second fractionating tower, means to separate the withdrawn liquid products into three distillates, and means for injecting the lightest distillate into the outlet of said third heating coil.

5. Apparatus of the character described comprising a heating coil, means for charging hydrocarbon oil to said coil, fractionating means connected to the outlet of said coil, a second heating coil, separate fractionating means connected to the outlet of said second coil, means for injecting an intermediate fraction separated in said first mentioned fractionating means into the outlet of said second coil, means for separating normally gaseous from normally liquid products in said second fractionating means, means for condensing and collecting a portion of said separated gases, at third heating coil, means for charging said condensed gases to said third coil, an absorber means for absorbing hydrocarbon gases in a solvent therefor, means for charging said enriched solvent to said third coil in admixture with said condensed gases, a clay tower connected to the outlet of said third coil, 2. by-pass around said tower, means connected to said clay tower for fractionating the products withdrawn therefrom, means for charging gases separated in said last mentioned fractionating means to the lower portion of said absorber, and means for charging heavy naphtha separated in said first mentioned fraotionating means to the upper portion of said absorber.

6. Apparatus of the character described comprising a fluid heating means, means for charging fluid into the outlet of said heating means, fractionating means connected to the outlet of said heating means, means for withdrawing gas and a plurality of liquid fractions from said fractionating means, means for transferring liquid from said fractionating means to said heating means, a second heating means, means for transferring gas from said fractionating means to said second heating means, a clay packed tower, means for transferring all the products from said second heating means directly to said clay packed tower, means connected to said first mentioned fractionating means for transferring liquid therefrom into the outlet of said second heating means, means for maintaining the aforesaid elements under superatmospheric pressure, fractionating means connected to the outlet of said clay contacting means capable of separating liquid from gaseous products and means for passing products from said second heating means directly to said last mentioned fractionating means.

7. Apparatus of the character described comprising a heating coil, means for charging hydrocarbon oil to said coil, fractionating means connected to the outlet of said coil, a second heating coil, separate fractionating means connected to the outlet of said second coil, means for injecting an intermediate fraction separated in said first mentioned iractionating means into the outlet of said second coil, means for separating normally gaseous from normally liquid products in said second mentioned fractionating means, means for condensing and collecting a portion of said separated gases, a third heating coil, means for charging said condensed gases to said third coil, an absorber for absorbing hydrocarbon gases in a solvent therefor, means for charging said enriched solvent to said third coil in admixture with said condensed gases, means for fractionating the products leaving said third coil, means for charging gases separated in said last mentioned fractionating means to the lower portion of said absorber, means for charging heavy naphtha separated in said first mentioned fractionating means to the upper portion of said absorber and a by-pass for charging said condensed gases from said condensing and collecting means to fractionating means without passing through said third coil.

8. Apparatus of the character described comprising a coil, means for heating oil in said coil to cracking temperature, means for charging fresh oil into the outlet of said coil, fractionating means connected to the outlet of said coil capable of separating the products issuing from said coil into residue, gas, gasoline and condensate heavier than gasoline, means for charging said heavier condensate to said coil, a second coil, means for charging said gas to said second coil, means for heating the gas in said coil to polymerizing temperatures, a tower packed with clay connected to the outlet of said second coil in such manner as to enable the entire products from said coil to pass through said tower, means for charging said gasoline into the outlet of said second coil, means for maintaining the aforesaid element's under super-atmospheric pressure, fractionating means connected to the outlet of said clay tower capable of separating liquid from gaseous reaction products, and means for passing products from said second coil directly to said last mentioned fractionating means.

9. Apparatus in accordance with claim 8 ineluding means for separating said gas into liquid and gaseous fractions, means for eliminating the gaseous fraction from the system, and means for charging the liquid fraction to said second coil.

10. Apparatus in accordance with claim 8 including an absorber, means for charging said gaseous reaction products under pressure to said absorber, means for charging hydrocarbon oil to said absorber wherein it contacts with said gaseous reaction products, and means for charging the enriched oil from said absorber to said second coil.

11. Apparatus in' accordance with claim 8 including an absorber, means for charging said gaseous reaction products under pressure to said absorber, means for charging a portion of said condensate heavier than gasoline to said absorber under pressure, and means for charging enriched oil from said absorber to said second coil.

12. Apparatus of the character described comprising means for separating crude oil into gasoline, heavy naphtha, gas oil and residuum, a cracking coil, means for charging said gas oil into the outlet of said coil, means for fractionating the mixed cracked products and gas oil into gas, gasoline, condensate heavier than gasoline, and residuum, means for charging condensate heavier than gasoline to said cracking coil under high super-atmospheric pressure, means for separating said gas into liquid and gaseous fractions, a polymerizing coil, means for charging said liquid gas fraction to said polymerizing coil, means for charging said gasoline to the outlet of said polymerizing coil, a clay tower connected to the outlet of said polymerizing coil in such manner as to enable the entire products leaving said coil to pass through the clay tower, means for maintaining the aforesaid elements under high super-atmospheric pressure, fractioning means connected to the outlet of said clay tower, in which liquid and gaseous products can be separated, an absorber, means for charging said gaseous products under pressure to said absorber, means for charging said heavy naphtha to said absorber, and means for charging enriched naphtha to said polymerizing coil.

13. Apparatus in accordance with claim 12 in which means are provided for passing the reaction products from said polymerizing coil into said last mentioned fractionating means without passing through said clay tower.

14. Apparatus in accordance with claim 12 including means for passing said liquid gas fraction directly to fractionating means without passing through said polymerizing coil or clay tower, and means to eliminate said gaseous prod ucts from the system.

15, Apparatus in accordance with claim 12 including means for charging products heavier than gasoline from said last mentioned fractionating means to said first mentioned fractionating means.

PERCY A. MASCI-IWITZ. 

